"The paper presents a major overhaul to the World Bank's past estimates of global poverty, incorporating new and better data. Extreme poverty-as judged by what "poverty" means in the world's poorest countries-is found to be more pervasive than we thought. Yet the data also provide robust...

Knowledge about development effectiveness is constrained by two factors. First, the project staff in governments and international agencies who decide how much to invest in research on specific interventions are often not well informed about the returns to rigorous evaluation and (even when they...

Standard methods of impact evaluation often leave significant gaps between what we know about development effectiveness and what we want to know-gaps that stem from distortions in the market for knowledge. The author discusses how evaluations might better address these knowledge gaps and so be...

Standard methods of impact evaluation often leave significant gaps between what we know about development effectiveness and what we want to know—gaps that stem from distortions in the market for knowledge. The author discusses how evaluations might better address these knowledge gaps and so be...